The present invention relates to a hybrid module for use in vehicles.
A trend toward the “hybridizing” of conventional motor vehicle drives has been discernible for a relatively long time. Some manufacturers offer vehicles with an automatic gearbox, optionally with or without an upstream “hybrid module.” For cost reasons, efforts are made to change or replace as few components as possible in the process of hybridizing.
It is an object of the invention to provide a hybrid module of simple and compact design by which an internal combustion engine can be coupled to a gearbox and with which a conventional drive train can be hybridized.
A hybrid module according to the invention comprises a housing, a rotary input, a rotary output, an electric machine arranged in the housing, as well as a separation clutch and a torsional vibration damper. The rotary input, identified hereinafter as the “input,” is provided for rotationally coupling the hybrid module with an internal combustion engine or a crankshaft of an internal combustion engine. The rotary output, identified hereinafter as the “output,” is provided for rotationally coupling the hybrid module to an input of a gearbox. The gearbox can be, for example, an automatic gearbox, a dual clutch gearbox, a manual gearbox, an automated manual gearbox or a gearbox of another type.
The electric machine arranged in the housing of the hybrid module has a stator fixed to the housing and a rotor which is rotatable relative to the stator. The rotor is designed and dimensioned such that the separation clutch and the torsional vibration damper can be arranged within the region enclosed by the rotor. The separation clutch and the torsional vibrator are therefore arranged (at least partially) “within” the rotor of the electric machine both in the radial direction and in the axial direction, thus enabling a very compact construction. For example, it can be provided that the separation clutch is arranged—seen from the input of the hybrid module in the direction of the output of the hybrid module—in front of the torsional vibration damper.
The separation clutch can be, in particular, a dry multi-plate friction clutch with a plurality of friction plate pairs. By installing a dry multi-plate friction clutch within the rotor of the electric machine and by integrating the torsional vibration damper in the space within the rotor of the electric machine, a relatively short structural length is achieved for the hybrid module. The multi-plate friction clutch can have two, three or more friction plate pairs.
According to one embodiment of the invention, the clutch has a non-actuated basic state in which the clutch is closed, i.e. so as to enable torque transmission. In order to open the clutch, a corresponding clutch hydraulic system can be provided, which has a hydrostatic actuator configured to match demand and able to be supplied with hydraulic energy.
In order to optimize the efficiency of the hybrid module, the friction plates of the clutch are fully separated in the open state. Therefore, in the open state of the clutch, the friction plates of the clutch do not contact one another. As a result, no friction heat is generated in the clutch in the open state thereof.
The input of the hydraulic module can be connected via the torsional vibration damper to the first friction plates of the clutch. The first friction plates can be radially inner friction plates (internal plates). The first friction plates cooperate with second friction plates which are arranged radially outwardly (external plates) in relation to the first friction plates. The second friction plates can be directly or indirectly connected to the rotor. The second friction plates therefore always rotate at the rotary speed of the rotor of the electric machine.
The first or second plates can be lined plates which are provided on both sides with a frictional coating. The lined plates are arranged to oppose friction partners made as steel or cast plates (second or first plates) by which, primarily, the heat that is generated is conducted away. Since steel or cast plates have a greater inertia than the lined plates, steel or cast plates are preferably arranged (for dynamic reasons) on the shaft which is static when the clutch is open.
The rotor of the electric machine can also be connected directly or indirectly to the output of the hybrid module, which is provided for rotationally coupling to the input of the gearbox.
According to another embodiment of the invention, the housing of the hybrid module is flanged, on an input side, to a crankcase of the internal combustion engine and, on an output side, to a housing of the gearbox. The housing of the hybrid module can be flanged directly or via an adaptor ring to the crankcase. Using an adaptor ring, the hybrid module can be combined with a variety of gearbox types.
According to another embodiment of the invention, the rotor of the electric machine is mounted in the housing of the hybrid module via sealed bearings in relation to the stator. The electric machine or the stator of the electric machine can be screwed onto the housing of the hybrid module or onto the adaptor ring as one “unit.”
In order to lift the friction plates on an internal plate carrier or external plate carrier, nodular washers or tangential leaf springs can be provided.
In order to actuate the separation clutch, as previously mentioned, a hydraulic system is provided. The hydraulic system is supplied with hydraulic pressure by a hydraulic pump. The hydraulic pump is driven by an electric motor. The electric motor used to drive the hydraulic pump can also be used as a drive motor of a gearbox oil pump of the gearbox connected to the hybrid module. The concerned electric motor, the hydraulic pump and the gearbox oil pump can be arranged outside the housing of the hybrid module and outside the housing of the gearbox.
The invention achieves the following advantages:
(1) A conventional drive train can be hybridized with the hybrid module according to the invention, the “basic gearbox” remaining, as far as possible, unaltered.
(2) The system for rotary oscillation reduction arranged on the gearbox input side with a conventional drive train is retained in principle, but is integrated into the hybrid module.
(3) The hybrid module can be combined with any gearboxes.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of one or more preferred embodiments when considered in conjunction with the accompanying drawings.